Mouldings provided with channels of above-mentioned type are known earlier, which consist of an extruded plastic profile, which is snapped firmly onto holders, firmly screwable on the wall, which in turn are formed with brackets for rigid bracing of the cable. One drawback with these mouldings is that if the cable should be led out of its place in the channel, either a notch must be cut out in the profile edge or a groove must be cut in the wall, through which the cable can be drawn. Wiring is often a temporary measure, as one wants to be able to change when refurnishing or at changed circumstances, and then the said grooves in the profile or channels on the wall are permanent measures, which one cannot make undone.